The instant disclosure relates to a family of devices and methods for both measuring electrophysiological signals and delivering elongate medical devices. In an embodiment, a kit is described that includes a hollow catheter adapted to navigate a patient's vasculature having a hollow lumen terminating at a distal end, structure configured for sensing cardiac electrical activity adjacent the distal end of the hollow catheter and for acquiring electrograms. The fossa ovalis of a subject can be located therefrom and a second medical device can be advanced into and through the hollow lumen to such an extent that a distal tip of the second medical device protrudes beyond a proximal end and the distal end of the hollow catheter at the same time.